The Collaborative International Dictionary of English v.0.48:
Polyvalent \Po*lyv"a*lent\, a. [Poly- + L. valens, p. pr. See Valent.] (Chem.) Multivalent. [1913 Webster]WordNet (r) 3.0 (2006):
polyvalent adj 1: containing several antibodies each capable of counteracting a specific antigen; "a polyvalent vaccine" [ant: monovalent] 2: having more than one valence, or having a valence of 3 or higher [syn: polyvalent, multivalent] [ant: monovalent, univalent]